The Village of Monticello Wastewater Treatment Facility

Author

Abigail Becker

Metrics

Wastewater treatment is the process of removing contaminants and creating an effluent that can be returned to the water cycle with minimal impacts. Municipal wastewater treatment includes
streams from household sewage and sometimes industrial wastewater. Physical, chemical, and
biological processes can be used to remove contaminants, including excessive nutrients, to produce
an effluent that is safe enough to be released to the environment.
Excessive nutrients (e.g. phosphorus, nitrogen) in the water causes algae to grow faster
than ecosystems can handle, which is called eutrophication. Significant increases in algae harm
water quality, food resources, and ecosystems by decreasing the oxygen that fish and other aquatic
life need to survive. Large growths of algae are called algal blooms; algal blooms can completely
eliminate oxygen availability in the water, which leads to decreases in biodiversity and increases
in water toxicity. Elevated toxin levels can be harmful to humans by direct contact or through
indirect pathways, such as the consumption of tainted fish or contaminated water. Therefore, it is
crucial to control nutrient levels, particularly limiting nutrients (e.g. phosphorus), to ensure the
well-being of the environment and society.
The effectiveness of phosphorus removal can vary, depending on the available equipment
and the treatment methods used. At the Monticello WWTF, phosphorus removal to the desired
levels (1 mg/L) is accomplished by alum addition. However, currently employed techniques are
not fulfilling the future phosphorus emission DNR limitations (0.075 mg/L). To meet the new
phosphorus effluent standards, two alternatives are analyzed in this report. The first alternative is
SorbX-100, which is a chemical treatment approach and uses a rare earth metal chloride solution
for phosphorus removal in municipal and industrial wastewater streams. The other alternative is
the CLEARAS ABNR System, which uses algae and other biological organisms to recover excess
phosphorus, nitrogen and other high-profile contaminants in wastewater. SorbX-100 and
CLEARAS ABNR systems have previously been tested in the Monticello WWTF as pilot systems
to evaluate their performance with respect to phosphorus removal. The system boundaries are set
to include input and output flows of material and energy resources for the operation of the systems
over a 20-year period.
The goal of this study is to assess and make a recommendation on the most appropriate
phosphorus removal strategy based on the three paradigm of sustainability (environmental,
economic, and social impacts). This goal is achieved by quantitatively modeling and evaluating
the environmental life cycle assessments, as well as social and economic assessments of the two
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phosphorus removal strategies applied at the Monticello WWTF (SorbX-100 and CLEARAS
ABNR). In this work, a comprehensive LCA, considering multiple impact categories, is performed
using SimaPro 8.5.2 Software and TRACI 2.1 Impact Assessment Methodology. Regarding the
environmental impacts, CLEARAS ABNR System is found to have less overall impact compared
to SorbX-100 (<7%). With respect to economic assessment, SorbX-100 is found to have less total present cost compared to CLEARAS ABNR System (~23%). Considering social aspects, both options proposes relatively comparable results. A weighting matrix is used to compare the two phosphorus removal options using the three paradigm of sustainability. The weights assigned to each paradigm were based on discussions with stakeholders of the Monticello WWTF. Environmental impacts are given a weight of one, economic impacts are given a weight of three, and social impacts are given a weight of one. Each of these weights were multiplied by the relative impact in comparison to the other option. Based on weighting matrix, the recommended option from this analysis is SorbX-100, which received a total sustainability score of 2.68 in comparison to CLEARAS ABNR which received 4.07. Even though the environmental impacts of CLEARAS ABNR were less significant than SorbX-100, the final recommendation is driven by the differences in economic impacts, which are more critical in this analysis. Read the final student report delivered to the local gov/community partner.

UniverCity Year Contact Info
Gavin Luter
Managing Director
gavin@cows.org
608-261-1141

University Faculty Contact
Andrea Hicks
Civil and Environmental Engineering

hicks5@wisc.edu

Local Government / Community Contact
Scott Anderson

Teacher at Juda School

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